Many wireless communication systems employ an interleaving scheme to reduce errors in transmission. Interleaving, for example, may help reduce the number of uncorrected error bursts, especially in fading channels. Interleaving is generally performed after channel encoding and permutes bits in a regular or predetermined fashion prior to modulation and transmission. Upon reception and after demodulation, a deinterleaving process is performed to restore the original bit sequence. Some orthogonal frequency division multiplexed (OFDM) systems use coding and frequency interleaving to help overcome problems associated with transmitting data over frequency-selective (i.e., fading) channels. Interleaving may exploit this frequency diversity by spreading adjacent bits across the transmission bandwidth.
Some multicarrier transmitters transmit more than one spatial stream on the same multicarrier communication channel. Conventional interleaving schemes may not provide sufficient bit separation between the subcarriers of these spatial channels. Conventional interleaving schemes may also not provide sufficient bit separation between bit positions of symbols. Thus there are general needs for multicarrier transmitters and methods of interleaving suitable for the transmission of more than one spatial stream.